OBJECTIVES/ISSUES ADDRESSED: Review the trends in estrogen use in the past decade by peri- and postmenopausal women. Discuss the current status of risks and benefits of estrogen use. APPROACH/METHODOLOGY: Abstract data on estrogen drug appearance from National Disease and Therapeutic Index volumes (1970-1978). Mortality and incidence data of endometrial cancer for the U.S. is also collected. Review current literature on estrogen as risk or beneficial factor. MAJOR FINDINGS: A drastic decline in estrogen drug appearances is observed during 1975-76 following the publication of several case-control studies linking estrogen use with endometrial cancer.